Systemisk mastocytos. Underskattat tillstånd hos patienter med oförklarad anafylaxi
Sammanfattning
Systemic mastocytosis (systemisk mastocytos) is a rare, clonal mast cell disorder and is characterized by expansion and accumulation of mast cells in the extra-cutaneous organs, such as bone marrow, lymph nodes, liver, spleen, and gastrointestinal tract. The clinical manifestation is extremely heterogeneous, and symtoms may range from asymtomatic to severe, potentially fatal, recurrent, unexplained anaphylaxis. The occurrence of mast cell clonality, which is the common etiology in these patients, can be confirmed by the detection of D816V c-kit mutation and/or occurrence of CD2+/CD25+ expressing aberrant mast cell phenotypes in the bone marrow. An increased level of baseline serum tryptase can be a distinguishing marker in differential diagnosis, however, final diagnosis can only be confirmed after a bone-marrow biopsy. The principle treatment during an acute attack is the same as for other types of anaphylaxis and prompt usage of intramuscular adrenaline is of crucial importance. Lifelong immunotherapy after hymenoptera stings should be considered in sensitized patients.